X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=fs%2Finode.c;h=76582b06ab975d76afcba7f5800d6c8e3873ebc6;hb=3e56d49390cd161f34cc049a3661045183d276d5;hp=901bad1e5f1210cce8f2bc2a474345f5b1a4072a;hpb=8123e8f7c89a07cb22279b15bf47cdee0205d4a1;p=karo-tx-linux.git diff --git a/fs/inode.c b/fs/inode.c index 901bad1e5f12..76582b06ab97 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -87,14 +88,18 @@ static struct hlist_head *inode_hashtable __read_mostly; DEFINE_SPINLOCK(inode_lock); /* - * iprune_mutex provides exclusion between the kswapd or try_to_free_pages + * iprune_sem provides exclusion between the kswapd or try_to_free_pages * icache shrinking path, and the umount path. Without this exclusion, * by the time prune_icache calls iput for the inode whose pages it has * been invalidating, or by the time it calls clear_inode & destroy_inode * from its final dispose_list, the struct super_block they refer to * (for inode->i_sb->s_op) may already have been freed and reused. + * + * We make this an rwsem because the fastpath is icache shrinking. In + * some cases a filesystem may be doing a significant amount of work in + * its inode reclaim code, so this should improve parallelism. */ -static DEFINE_MUTEX(iprune_mutex); +static DECLARE_RWSEM(iprune_sem); /* * Statistics gathering.. @@ -120,12 +125,11 @@ static void wake_up_inode(struct inode *inode) * These are initializations that need to be done on every inode * allocation as the fields are not initialised by slab allocation. */ -struct inode *inode_init_always(struct super_block *sb, struct inode *inode) +int inode_init_always(struct super_block *sb, struct inode *inode) { static const struct address_space_operations empty_aops; - static struct inode_operations empty_iops; + static const struct inode_operations empty_iops; static const struct file_operations empty_fops; - struct address_space *const mapping = &inode->i_data; inode->i_sb = sb; @@ -152,7 +156,7 @@ struct inode *inode_init_always(struct super_block *sb, struct inode *inode) inode->dirtied_when = 0; if (security_inode_alloc(inode)) - goto out_free_inode; + goto out; /* allocate and initialize an i_integrity */ if (ima_inode_alloc(inode)) @@ -183,9 +187,7 @@ struct inode *inode_init_always(struct super_block *sb, struct inode *inode) if (sb->s_bdev) { struct backing_dev_info *bdi; - bdi = sb->s_bdev->bd_inode_backing_dev_info; - if (!bdi) - bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; + bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; mapping->backing_dev_info = bdi; } inode->i_private = NULL; @@ -198,16 +200,12 @@ struct inode *inode_init_always(struct super_block *sb, struct inode *inode) inode->i_fsnotify_mask = 0; #endif - return inode; + return 0; out_free_security: security_inode_free(inode); -out_free_inode: - if (inode->i_sb->s_op->destroy_inode) - inode->i_sb->s_op->destroy_inode(inode); - else - kmem_cache_free(inode_cachep, (inode)); - return NULL; +out: + return -ENOMEM; } EXPORT_SYMBOL(inode_init_always); @@ -220,12 +218,21 @@ static struct inode *alloc_inode(struct super_block *sb) else inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL); - if (inode) - return inode_init_always(sb, inode); - return NULL; + if (!inode) + return NULL; + + if (unlikely(inode_init_always(sb, inode))) { + if (inode->i_sb->s_op->destroy_inode) + inode->i_sb->s_op->destroy_inode(inode); + else + kmem_cache_free(inode_cachep, inode); + return NULL; + } + + return inode; } -void destroy_inode(struct inode *inode) +void __destroy_inode(struct inode *inode) { BUG_ON(inode_has_buffers(inode)); ima_inode_free(inode); @@ -237,13 +244,17 @@ void destroy_inode(struct inode *inode) if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) posix_acl_release(inode->i_default_acl); #endif +} +EXPORT_SYMBOL(__destroy_inode); + +void destroy_inode(struct inode *inode) +{ + __destroy_inode(inode); if (inode->i_sb->s_op->destroy_inode) inode->i_sb->s_op->destroy_inode(inode); else kmem_cache_free(inode_cachep, (inode)); } -EXPORT_SYMBOL(destroy_inode); - /* * These are initializations that only need to be done @@ -375,7 +386,7 @@ static int invalidate_list(struct list_head *head, struct list_head *dispose) /* * We can reschedule here without worrying about the list's * consistency because the per-sb list of inodes must not - * change during umount anymore, and because iprune_mutex keeps + * change during umount anymore, and because iprune_sem keeps * shrink_icache_memory() away. */ cond_resched_lock(&inode_lock); @@ -414,7 +425,7 @@ int invalidate_inodes(struct super_block *sb) int busy; LIST_HEAD(throw_away); - mutex_lock(&iprune_mutex); + down_write(&iprune_sem); spin_lock(&inode_lock); inotify_unmount_inodes(&sb->s_inodes); fsnotify_unmount_inodes(&sb->s_inodes); @@ -422,7 +433,7 @@ int invalidate_inodes(struct super_block *sb) spin_unlock(&inode_lock); dispose_list(&throw_away); - mutex_unlock(&iprune_mutex); + up_write(&iprune_sem); return busy; } @@ -461,7 +472,7 @@ static void prune_icache(int nr_to_scan) int nr_scanned; unsigned long reap = 0; - mutex_lock(&iprune_mutex); + down_read(&iprune_sem); spin_lock(&inode_lock); for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { struct inode *inode; @@ -503,7 +514,7 @@ static void prune_icache(int nr_to_scan) spin_unlock(&inode_lock); dispose_list(&freeable); - mutex_unlock(&iprune_mutex); + up_read(&iprune_sem); } /* @@ -689,13 +700,15 @@ void unlock_new_inode(struct inode *inode) } #endif /* - * This is special! We do not need the spinlock - * when clearing I_LOCK, because we're guaranteed - * that nobody else tries to do anything about the - * state of the inode when it is locked, as we - * just created it (so there can be no old holders - * that haven't tested I_LOCK). + * This is special! We do not need the spinlock when clearing I_LOCK, + * because we're guaranteed that nobody else tries to do anything about + * the state of the inode when it is locked, as we just created it (so + * there can be no old holders that haven't tested I_LOCK). + * However we must emit the memory barrier so that other CPUs reliably + * see the clearing of I_LOCK after the other inode initialisation has + * completed. */ + smp_mb(); WARN_ON((inode->i_state & (I_LOCK|I_NEW)) != (I_LOCK|I_NEW)); inode->i_state &= ~(I_LOCK|I_NEW); wake_up_inode(inode);